I learned the term "Compression of Morbidity" from Dr. Andrew Wiel, while watching a PBS special. The term refers to one living as healthily and long as possible, before quickly dying with as little loss in quality of life as possible. Live well, and then exit quickly. Both links below have vaild points of view. If I can live to 90 while being physically mobile, and mentally agile, then I would certainly love to stick around. If I make it to 90 just limping along both mentally and physically, then I would agree with Ezekial Emmanuel's article Why I Hope to Die at 75
Having read Jacqueline Damian's response (Is Age 75 the 'Right' Time to Die), I do find myself disagreeing with her assertion that old age might be about "down shifting", and that doing nothing is actually doing something important. I feel like ultimately we are both physical and mental creatures, and that one without the other is diminished capacity. My biggest issue with her response is that I think she assumes ones' mental faculties can survive beyond the physical. I certainly believe that might be true for some, but I definitely don't believe that this is true for all, or even necessarily true for the majority.
The article that actually started me off down this rabbit hole, popped in my facebook feed a few days ago. It's about a 75 year old crossfitter's response to Ezekial Emmanuel's original article, and the article title is A 75-Year Old CrossFitter vs. Ezekiel Emanuel. In this post, Jacinto Bonilla shows how we can be both physically excellent, and mentally alert as we enter old age. I'm thankful to have pretty good examples of this in my family. My Great Grandpa on my Father's side lived into his 90s with great mobility. He was a very slight man at that age, but he regularly navigated a steep hill to his garden, and tended his apple trees. My Mother's Dad also lived into his late 80s still performing pushups, but quickly succumbed to an esophageal tumor. My Dad is currently in the second half of his 60s and is still powerlifting.